Amaranth (Amaranthus spp.), a gluten-free pseudocereal, is rich in protein and bioactive compounds (phenolic compounds, squalene, phytosterols, tocopherols, and dietary fiber), making it a valuable ingredient for improving the nutritional quality of baked goods. Incorporating amaranth flour into wheat bread, especially via sourdough fermentation, may enhance both nutritional and sensory properties. This study investigates the impact of adding amaranth sourdough at various levels on the quality characteristics and nutritional value of wheat bread. Commercial wheat flours of type 405 and 750 were used, with a portion of the wheat flour substituted by ground amaranth grain at levels of 5%, 10%, and 15% in the form of sourdough. A control sample consisting of wheat bread without amaranth flour (0%) was also prepared.

The research included the assessment of the quality parameters of amaranth grain flour and wheat flours, such as protein, ash content, and moisture, as well as gluten yield and spreadability, falling number, and Zeleny sedimentation index. For the baked breads, evaluations included overbake, specific volume, crumb porosity (Dallman scale), crust and crumb color, texture profile analysis (TPA), organoleptic assessment, and nutritional analysis based on crumb moisture, protein, and total ash content. The average energy value and nutritional content per 100 g of flour blends used in baking (protein, lipids, carbohydrates, and fiber) were also calculated.

The enrichment of wheat bread with amaranth sourdough positively influenced the quality parameters and nutritional profile of the final products, particularly in terms of protein and ash content. The addition of amaranth flour contributed to an increase in loaf volume. Bread containing 5% amaranth flour in the form of sourdough demonstrated improved hardness, springiness, gumminess, and chewiness compared to the control sample. The maximum share should not exceed 10%.